Drier kiln



H. R, STRAIGHT DRIER KILN Dec. 14 y1926.

Filed Jan. 12, 1925 Fill Dec. 14 1926.

H. R. STRAIG HT DRIER KILN Filed Jan. 12. 1925 2 Sheets-Sheet 2 Patented Dec. 14, 1926.

UNITED STATES PATENT oEEicE.

HALVER R. STRAIGHT, V]? ADEL, IOWA.

DRIER KILN.

Application filed January 12, 1925.

very rapidly without warping or checking the same.

A further object is to 'provide in a drier lmeans for imparting a continuous circulating movement to the drying medium and to arrange the kiln in a series of compartments or chambers so thatas the ware is advanced through the kiln, it may undergo a series ot successive stages oi drying, cach of the chambers and circulating` means being so arranged that as the ware enters the iirst drying chamber, the process will be comparatively slow, but as 'the ware is advanced through the-kiln, the drying process may be proportionately increased, so as to prevent the ware from cracking or warping. I have found by experiment that the ware shrinks very rapidly while the lirst portion ot' the moisture is being removed. That is, when about ten percent of the moisture has been removed, thirty percent of the total shrinkage has taken place, and when seventy percent ot the moisture has been removed, the tot-al amount of shrinkage has taken place, the ware having a tendency to expand while the last thirty percent of the moisture is being removed.

A further object is to provide a drier kiln having means for imparting a continuous circulation of the drying medium in such a manner that the drying mediumwill beY introduced tirst to the receiving compartment or chamber ot the kiln at a compara tively high humidity. and the warm medium being introduced `from above'the ware and caused to move downwardly through the same, the medium being cooled by the ware and at the same time removing a portion of the moisture. rI he medium is then brought into contact with a cool plate or surface,` so as to condense a large portion ot' the moisture received and then moved upwardly through a. bypass and heated as it travels Serial No. 1,970.

through the said by-pass, and again introduced into the second receiving compartment or chamber at a higher temperature than when introduced to the first` compartment and again allowed to move downwardly through the ware and to have the moistureV removed by coming in contact with a cool or chilled plate. This operation is to be continued throughout the entire length of the-kiln. The object of this method of circulating the air is to keep the air currents moving in a natural manner as they are passed through the ware, so the ware will be come uniformly dried, as I have found by experiment that hot air moving downwardly i through cooler ware will travel more unitormly through the ware than if it were forced upwardly as the cooler currents produced by the ware would cause eddy currents and uneven drying would result.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more tuily set forth, pointed out in my claims, and illustrated in the accompanying` drawings, in which:

Figure l is a plan view of a portion of my improved drier kiln.

Figure 2 is a longitudinal sectional view taken on the line 2 2 of Figure l.

Figure 3 is a longitudinal sectional view taken on the line 3 3 of Figure l.

Figure 4 is an end elevation of a portion of my improved kiln.

Figure 5 is an enlarged, detail. sectional View taken on the line 5 5 of Figure 3.

Figure 6 is a detail sectional view taken on the line 6-6 of Figure 3.

Figure 7 is a detail sectional view taken on the line 7-7 of Figure 3.

My improved kiln comprises a series of parallel foundation members 10, each of which is provided with a wall 1l which is formed hollow to form a passageway. Each of the passageways is provided with a cover 12. Supported on the upper surface of the cover l2 is a sheet metal plate 13 which is somewhat higher at its central portion midway between the members l2, so as to form an inclined floor.

Mounted on top of each ot the plates 12l I have provided a series of upright Lbeams lll, the upper ends ot which are designed to carry the top l5 ot the kiln. By this arrangement it will be seen that the beams 14 lll are arranged in rows, each row being verically above the plate 12 upon which it rests, and extending longitudinally therewith.

That portion of the cover 15 which rests.

between two adjacent rows ol uprights 14 has its central portion depressed longitudinally with said rows, so as to form a roof for the interior of the kiln having its under surface declined downwardly and inwardly for the purpose hereinafter made clear.

Adjacent to each side of the members 14, I' have provided a sheet metal wall 16, so as to form a vertical passage l? between said walls and between the members 111, the upper edges of the members 16 being of a height considerably less than the height of the members 14. rThe lower edges of said members 16 being mounted a slight distance above the plate 12.

That portion of the lower edge of each ot said plates 16 which extends between two adjacent uprights 12 is provided with a horizontal portion 18 and an inclined por tion 19, said inclined portion extending downwardly and rearwardly. he lower edges of the nvembers 18 and 19 are provided with a transversely arranged plate 2O to form a floor or bottom for the compartment which is formed between two of the plates 16. By this arrangement it will be seen that a portion of the floor 2O liesina horizonal plane while the other portion is inclined downwardly and rearwardly.` A vertical.

cross partition 21 is provided at the forward edge of each of the floor members 20.

Extending transversely between each pair of plates 16, I have provided a supporting` rail 22 which is designed to carry a pair of longitudinally extending tracks 23, said tracks 23 extending longitudinally throughout the entire length ofjthe' passagel formed between the plates 16,fand through a room 2d which extends transversely across the rear end ot' all of tlle passages formed between each set of plates 16, as illustrated in Figures 2 and 3.

The room 24 is provided with an end member 25 which has openings 26 in alinement with the tracks 23. The tracks 23 are designed to receive a continuous c-onveyor 27 on which are carried a series of transversely arranged pallets 23, said pallets being of a length slightly less than the width of each of the longitudinal compartments, and are designed to pass through the opening 26 in the end plate 25. A second set of track members 29 is provided beneath the sheet metal plate 13 to larrv the lower run of the conveyor 27. i

The forward end of the longitudinal coinpartments is provided with an end 30 havinfr openings 31 for the said conveyor, and

through which the pallets 28 are caused to enter the compartments. The conveyor 27 is also mounted on suitable sprockets 32 and 33, which are driven through any suitable mechanism, and which form no part of my present invention.

Arranged immediately above each of the partitions 21 is a parfition 34 which extends upwardly to the top 15. The lower edge of the partition 34 is of such height as to permit the ware, which rests on the pallets 28, to pass beneath.

By this aranle'ement, it will be seen that l have provided a series of longitudinal compartments la, which are between the plates 16, and each of said compartments being divided into a series of chambers B, C, D and E, which are between the transversely arranged plates 21 and 311.

At the forward end of the passage 12 (beneath the plate 13, l have provided a compartment F, in which is mounted a motor driven blower 35, which is provided with an inlet pipe 36, extending through the floor plate 13 communicating with the bottom of the chamber E The blower is provided with a discharge pipe 37 which extends into the passage G of the foundation mem ber 11.

lt will be seen in Figure 3, that the upright members 14 divide the passage between the plates 16 into a series of passageways H, I, J and K. It will further be seen that the plate 12 is provided with a slot 38 which places the passage G into communication with the passage H, and that if the blower is operated, the drying medium may be drawn from the chamber E and discharged into the. passage G upwardly through the slot 38 into the passage H over the top edge of the plate 16 to two adjacent chambers B, where it will pass downwardly through the ware on the conveyor, and beneath the plate 20 of the chamber C, after which it will be moved upwardly through the passage l into the chambers C This operation will be repeated for all of the chambers a. D and E, and the drying medium again returned to the blower 35.

For heating the medium as it passes upwardly through the passages H, l, il and K, I have provided a pipe 39 which extends longitudinally through the member: 14e, and between the passages H l fl and K, the rear end of which extends upwardly and rearwardly to a combustion chamber 40, which may be supplied with vaporous fuel through the burner h/1-1. The opposite end of the pine 39 is provided with an upwardly extending` portion 42. which acts as a flue. The forward ends of the compartments A are provided with a transversely arranged passage L having a cover plate 43. The plate 43 is provided with upwardly extending pipes 14, each of which is provided with a butterfly damper 45, said damper being` designed to be opened and closed by means of a thermostat 4G. The passage L is provided with an exhaust fan for the purpose ot maintaining a partial vacuum therein, said tan having'` a conductor neither fan nor conductor being illustrated in the drawings. The rear end of the passages A, as before described, are in communication with the room 24, and the end member is provided with draft doors 47 located above the openings 26, and draft doors 48 located beneath the openings 26.

Thus it will be seen that if pallets are fed to the receiving end of the conveyor Q7, said receiving` end being at the right hand end oit the kiln, as illustrated in Figures 2 and 8, and moved continuously or intermittently through the kiln, and that if the burners 41 are supplying heat to the pipes 43, and the blowers are being continuously operated at a uniform speed, and a partial vacuum is being maintained in the passage L, then a drying medium willbe drawn from the chamber E through the blower 85 and discharged into the passage G then through the slot 38 upwardly through the passage H around the heating pipe 39, where the medium will be slightly heated. 1t will then pass over the top edge of the plate 16 into the two adjacent compartments B, and Vcirculate down through the ware on vthe conveyor 27, and then be moved rearwardly to the passage beneath the plate 20 of the chamber C It willY be seen that the warm medium will become cool as it passes through the ware, and the cool and partially saturated medium will settle on the plate 13, where a large part oit its moisture will be condensed, due to the fact that cold air is being drawn through the doors 47 and 48 and through the passage beneath the plate 18 through the pipes and through the passage L, This air is considerably cooler` than the drying medium. The medium will then move into the passage I around the pipe 39, and will again be heated at a somewhat higher temperature than whenit went through the pas-- sage H, due to the fact that the passage I is closer to the heated en'd ot the pipe 39. It will then be drawn again downwardly through the ware in the chamber C and again engage the plate 18, whereby the moisture will be extracted before described'.

This cycle ot operation is continued until the drying medium has again reached the blower The temperature ot `the medium is increased each time it ypasses from one chamber to the next. Va-re then mim'ed into the room 24 where the cool air is passed down through the ware, the ware being cooled bet'ore it leaves the kiln.

The circulation ot the air through the ware in the room 24 may be regulated by proper manipulation of the doors 47 and 48. It too much air is passing through the ware, thenv the door 47 is closed and the doors 48 opened, or vice versa. The temperature of theplate 13 may be constantly maintained by means oiE the thermostatic valve 46, the valve closing it the 4 temperature of the air in the com,- partment under the plate 13 falls too fast. It is understood that air circulating through the ware in the room 24 becomes heated, due to the heated ware coming from the chamber E The air beneath the plate 13 may then be easily maintained at an even temperature by opening and closing a thermostat valve to increase or decrease the amount of atmosphere received. The condensed moisture may be removed through downwardly eX- tending pipes 49 from the plates 13, the moisture being carried ott by suitable pipes 50.

l find, however, that in real hot weather, when the mean temperature of the atmosphere is near 100, that it is impossible to draw air through the door opening 47 and downwardly through the ware, and at the same time keep the plate 13' cool enough to produce the proper condensation.

To overcome this diiliculty, I have provided a vertical flue 48a in the top part of the chamber 24 having a valve 48h. By this arrangement, it will be seen that by opening both the doors 47 and 48, the heated air within the upper portion ot the chamber 44 will be forced upwardly through the pipe 48, while cool air may be admitted through the door opening 48 to the plate 13, and produce the necessary condensation. In winter weather, when the outside atmosphere is cold, the memberI 48b may be closed and the device operated as above described.

To assist in distributing the air more uniforn'ily in the chambers .B, (1, D and 112, l have provided a series of downward` ly extending detlector plates 51, which are extended longitudinally with the passage A and serve to prevent direct cross currents over the top o't the plates 1G. It will be vseen that the chamber B is considerably longer than the chamber Cf which is for the purpose of permitting the drying medium to move through the ware at a slow rate ot speed as the ware lirst enters the kiln. As before stated, a large percentage ot the shrinkage takes place in this chamber, and ior that reason the circulation of the medium must be slow, so as to not cause a too rapid shrinkage of the ware. The velocity ot the medium is higher in the bal-` ance ot the chambers. Y

By this arrangement it will be s'een that l have provided a drier kiln which is very elticient in its operation, diie to the tact that the drying medium is caused to be continuously recircnlated through the ware, and may be er ily maintained at the proper temperature tor the most efficient work, regardless ot thetcmL erature of the atmosphere which is variable. The temperature of the drying medium is easily maintained, due to the fact that the burner, when properly adjusted,v

will give a unit'orm supply of heat, and turther due to the tact that the percentage of the moisture removed from the ware is practically uniform, and further due to the fact that the cooling ot the plate 13 is constantly maintained by the thermostatic regulator. The medium is easily circulated at a constant velocity by the Velectrically driven blower, the only variable element being in the atmosphere which enters the chamber 24, this being regulated through the thermostat as before described, which provides means for regulating` the percentage of humidity in the drying medium, it always being desirable to maintain a constant amount ot humidity.

This arrangen'ient has a further advantage in that the drying in the various chambers is very uniform, due to the tact that the drying` medium is heated, and then passed into the upper part of the drying chambers where it moved downwardly in a natural f', manner. In other words` the draft is practically a natural draft. The medium being cooled as it comes in contact with the ware, naturally settles dmvnwardly. All ot the upwardly moving currents are maintained in separate passages, thereby eliminating any tendency toward dead spots or eddy currents which are always in existence when an attempt is made to move the drying medium upwardly through the ware.

I claim as my invention:

l. A drier comprising a series of longitudinally extending and parallel passages, means for moving ware horizontally and longitudinally through said passages, each of said longitudinal passages being divided into a series of chambers, and means for circulating a drying medium in a continuous manner and successively through each of said chambers and in a downward movement through the ware.

2. A drier comprising a series ot longitudinally extending and parallel passages, means for moving ware horizontally and longitudinally through said passages, each ot said longitudinal passages being divided into a series of chambers, means for circulating a drying medium in a continuous manner and successively through each of said chambers and in a downward movement through the ware, means for extracting a portion of the moisture from the driving medium after it has moved downwardly through the ware in each of its successiv-e downward movements, and means for successively heating the medium and moving it upwardly between each of its 'downward movements.

3. A drier having a drying compartment provided with a by-pass passage. means for moving ware horizontally through said compartment, means for moving a drying medium alternately upwardly and downwardly, the drier being so arranged that the drying medium will pass through the-ware in its downward movements and through said bypass passage in its upward moveuients, and means for independently heating the medium in each successive upward movement, the medium in each succeeding upward movement being brought to a temperature higher than the preceding movement.

4. A drier comprising a compartment provided with a by-passage, means for moving ware horizontally through said compartment, means tor moving a drying medium alternately upwardly and downwardly, the drier being so arranged that the drying medium will pass through the ware in its successive downward movements and through said by-pass passage in its upward movements, means for independently heating the medium in each successive upward movement, the medium in each succeeding upward movement being brought to a temperature higher than the preceding movement, and means Jfor lowering the temperature of the drying medium at the end ot each successive downward movement for the purpose ot condensing moisture. therein.

5. A drier comprising a compartment provided with a by-pass passage, means tor moving ware horizontally through said compartment, means for moving a drying medium continuously upwardly and downwardly, the drier being so arranged that the drying medium will pass through the ware in its successive downward movements and through said by-pass passage in its upward movements, means Yfor independently heating the medium in each successive upward movement, the medium in each succeeding upward movement being brought to a temperature higher than the preceding movement, and means operated independently from the continuous drying medium for cooling the ware after it has passed through the continuously circulated medium.

G. A drier comprising a series oi" parallel compartments, means for moving ware horizontally and longitudinally through said compartments, a cooling room adjacent to one end ot said compartments, said compartments being arranged in a series ot chambers, the partitions ot said compartments being provided with passages, said passages being provided with heating means, means for moving a drying medium upwardly through said passages and past the drying means and thence downwardly through said chambers in a successive manner and circulating through the ware in itsI downward movement, a plate beneath said chambers for receiving the cool and moisture laden medium, means 'for circulating air at atmospheric temperatures through the ware in said cooling chamber, and then beneath llO the cooling plate oi said chambers, and ther- .mostatic means for controlling thecirculation of said air. p

7 In a drier, means for advancing ware through the drier, means for .circulating a drying medium in such aV manner that the drying medium will be passed downwardly through the ware in a ,Series ot' successive movements and progressive in the sam-e direction as the movement ot said ware.

8. In a drier, means for advancing ware through the drier, means for circulating a drying medium in such ya manner that the drying medium will be passed downwardly through the ware in a series of successive and vertical movements and progressively in the sam-e direction as the movement of said ware, means for ley-passing and moving the medium upwardly between each successive downward movement, and means i'or heating the upwardly moving medium.

9. A drier comprising parallel wall members, means Yfor advancing ware through the kiln between said wall members, said kiln having its ceiling inclined downwardly and inwardly from each ot its side edges.

10. A drier comprising parallel wall members, means for advancing ware through the kiln between said wall members, said kiln having its ceiling inclined downwardly and inwardly from each of its side edges, and a series ot deflector plates depending from the under surface of said inclined ceiling.

11. A drier kiln, means for supporting ware within the kiln, a passageway extending the entire length of one side of said kiln and communicating with the top portion ot the interior of said kiln, a heating element extending longitudinally through said passageway, said heating element being of such diameter' as to provide a restricted passageway between it and the side walls of said passage, means `for moving a drying medium upwardly through said passageway to thev interior of said kiln.

12. A drier having a drying compartment, means for advancing ware through said drying compartment at a uniform rate of speed, means for circulating a drying medium uniformly through the ware ata constant rate of speed, means for supplying a uniform amount of heat to the drying medium as it is being circulated` means for condensing the moisture from the drying medium, and means for automatically controlling the said condensing means. r

18. In a drier kiln, means for supporting ware within the kiln, means for circulating a drying medium in a continuous manner, said circulating means being so arranged that the medium will be passed through the ware in a succession of downward movements and upwardly in a succession of vertical movements, means for heating the medi'mu as it passes threngh the successive upm ward movements, so that the drying medium is at a temperature higher than that of the ware, and means tor cooling the medium at the end of each of its downward movements to cond-ense moisture therefrom.

141.V In a drier kiln, means for supporting ware wit-hin the kiln, means for circulating a drying medium in la continuous manner, said circulating means being vso arranged `that then'iedium will be passed through the ware in a succession of downward movements and upwardly in a succession ot vertical movements, means for hea-ting the medium as it passes through the successive upward movements, so that the drying medium is at a temperature higher than that of the ware,

means for coo-ling the medium at the end of each of its downward movements to conuense moisture therefrom, means adjacent to said medium circulating means for circulating air at atmospheric temperatures through the ware as it is discharged from the irst said circulating means and for supplying the cooling medium for said condensing means, and means for automaticallyV regulating the temperature of said-condensing means.

15. A drier having a drying compartment, means for moving ware horizontally through said compartment, a cooling plate beneath said ware, means for moving a drying medium alternately upwardly and downwardly through the ware in a successive manner, means for heating the medium in its upward movements, the medium being` designed to engage said plate on each of its downward movements, means at the delivery end of said drier for conducting air at atmospheric temperatures through said ware and adjacent to the under side of said plate, a thermostatic regulator 'for controlling the amount of air which engages said plate.

16. In a drier, means for advancing ware through the drier, means for circulating a drying medium in such a manner that the drying medium will be passed downwardly through the ware in a series of successive and vertical movements and'progressive in the same direction as the movement of said ware, means for lay-passing and moving the medium upwardly between each successive downward movement, means for heating the upwardly moving medium, and means for continuously recirculating said medium.

17. In a drier, means i'or advancing ware through the drier, means for circulating a drying medium in such a manner that the drying medium will be passed downwardly through the ware in a series of successive movements and progressive in the same di-` rection as the movement of said ware, and means for continuously recirculating said medium.

18. A drier having a drying chamber and eenling compartment, means for advanctl e,

mg @infringir drying; chamber aus said `cooling compartment, means for Cireulating a drying medium through the ware as it passes through said chamber, means for heating the said medium te bring the ware to a warm temperature, an exhaust llue in Communication with the top of said eooling Chamber, said cooling Chamber being provided with an inlet opening above the ware and a,y second inlet opening below the ware, means for closing each ot' said openings, means for closing said exhaust flue, means for producing a partial vacuum within said cooling Chamber.

19. A drier comprising a drying Chamber and a cooling compartment means for moving ware horizontally through said Compartment, means for moving a drying medium through said ware in a succession of downward movements, a condenser plate beneath vthe said drying chamber so arranged that the currents of drying medium will engage said plate during each of its downward movements, said cooling compartment being provided with an exhaust Hue in its upper portion, an inlet opening above the ware, and a second inlet opening below the ware, an adjustable door for each of said openings, a valve for said exhaust flue, and means for exhausting the air from said eooling chamber and moving it in Contact with the under surface of said plate.

20. A drier having a drying compartment, means for moving ware horizontallv through said compartment, means for nioving a drying mediun alternately upwardly and downwardly, the drier being so arranged that the drying medium will pass through the ware in its dowi'iward movements, means for heating the mediuni in its ugward movements.

2l. A drier` having a drying Compartmenti`r means for moving ware horizontally through said compartment, means for moving a drying medium alternately upwardly and downwardly, the drier being so arranged that the drying medium will pass through the ware in its downward movements, means for heating the medium in its upward movements, and means for Condensing a portion of the moisture from the niedium in each of its downward movenjients.

Des Moines, Iowa, January 6, 1925.

HALVER R. STRAGHT. 

